Chrysanthemum plant

ABSTRACT

An induced mutation of Frost characterized by its yellow ray florets.

The present invention comprises a new and distinct cultivar of Chrysanthemum morifolium Ramat., hereinafter referred to by the cultivar name Yellow Frost (#72072B13).

Yellow Frost is a product of planned sport induction program which had the objective of expanding the color range of the parental cultivar, Frost (#72072013: disclosed in our U.S. Plant patent application filed Aug. 23, 1976, Ser. No. 716,438).

Yellow Frost was discovered and selected by William E. Duffett and Walter H. Jessel, Jr. on May 20, 1975 as one plant within a flowering block of Frost in a controlled environment in Barberton, Ohio. Plants within the flowering block were derived from stock plants which had been irradiated as rooted cuttings with an x-ray source of 1800 r units.

The first act of asexual reproduction of Yellow Frost was accomplished when vegetative cuttings were taken from the initial selection in October, 1975 in a controlled environment in Barberton, Ohio by a technician working under formulations established and supervised by Walter H. Jessel, Jr. and William E. Duffett. Horticultural examination of selected units initiated Mar. 29, 1976 has demonstrated that the combination of characteristics as herein disclosed for Yellow Frost are firmly fixed and are retained through successive generations of asexual reproduction.

Yellow Frost has not been observed under all possible environmental conditions. The phenotype may vary significantly with variations in environment such as temperature, light intensity, and day length. The following observations, measurements, and comparisons describe plants grown in Barberton, Ohio under greenhouse environmental conditions which approximate those generally used in commercial practice, as described in Chart A which appears at the end of the present specification. A light intensity chart of general use is shown in ASHAE Trans., Vol. 64, page 64, and reference is made thereto.

The following traits have been repeatedly observed and are determined to be basic characteristics of Yellow Frost which in combination distinguish this chrysanthemum as a new and distinct cultivar:

1. Spooned daisy capitulum type.

2. Flat capitulum form.

3. Medium yellow ray floret color.

4. Yellow-green (immature) to yellow (mature) disc floret color.

5. Diameter across face of capitulum from 80 to 95 mm. at maturity.

6. Uniform 9 week flowering response to photoperiodic short-day control.

7. Medium plant height (requires 1-2 long day weeks prior to short days to obtain a flowered plant height of 72 to 82 cm. when grown as a single stem plant for May through October flowerings.)

8. Semi-spreading branching pattern.

9. Minimal pollen development.

The accompanying color photographic drawing shows typical inflorescence and foliage characteristics of Yellow Frost. Color representations are as nearly true as possible with illustrations of this type.

Of the many commercial cultivars known to the present inventors, the most similar existing cultivar in comparison to Yellow Frost is the parental cultivar, Frost. Reference is made to attached Chart B which compares certain characteristics of Frost with the same characteristics of Yellow Frost. As noted in Chart B, the primary distinguishing characteristic of Yellow Frost in comparison to Frost is that of ray floret color. All other characteristics of Yellow Frost are similar to those same characteristics of Frost.

In the following description, color references are made to The Munsell Limit Color Cascade, 1972 edition. The color values were determined between 3:30 and 4:00 P.M. on Dec. 30, 1976 under 150 foot-candle light intensity at Barberton, Ohio.

Botanical classification: Chrysanthemum morifolium, Ramat., cv Yellow Frost.

INFLORESCENCE

Capitulum:

Form.--Flat.

Type.--Spooned daisy.

Diameter across face.--80 to 95 mm.

Corolla of ray florets:

Color (abaxial).--25-4.

Color (adaxial).--25-2.

Corolla of disc florets:

Color.--22-8 (immature) to 26-6 (mature).

Reproductive organs:

Androecium.--Present disc florets only.

Gynoecium.--Present both ray and disc florets.

PLANT

General appearance: semi-spreading branching pattern; medium height.

Foliage:

Color (abaxial).--Approximately 19-15.

Color (adaxial).--Approximately 19-13 to 19-14.

                                      CHART A                                      __________________________________________________________________________     AVERAGE GREENHOUSE CHRYSANTHEMUM ENVIRONMENTS                                  USED FOR BARBERTON, OHIO                                                       TEMPERATURES USED                                                                        Bright                                                                              Cloudy                                                                             LIGHTING                                                                               BLACK CLOTH                                                                             SUPP                                       SEASON                                                                               Night                                                                              Day  Day USED    USED     CO.sub.2                                   __________________________________________________________________________           65° F                                                                       65° F                                                                        60° F                                                                       2 to 4 weeks                                                                           To Sept. 15                                                                             From                                                          at 3 Hours Per                                                                         on - 5:30 PM                                                                            Oct 15                                     FALL  to  to   to  Night                                                             56° F                                                                       80° F                                                                        75° F                                                                       of 7-10 f.c.                                                                           Off - 7:30 AM                                                                           300 ppm                                          58° F                                                                       65° F                                                                        60° F                                                                       2 to 5 weeks                                                                   at 5 Hours Per                                              WINTER                                                                               to  to   to  Night   None     300 ppm                                          62° F                                                                       70° F                                                                        65° F                                                                       of 7-10 f.c.                                                      58° F                                                                       65° F                                                                        60° F                                                                       2 to 4 weeks                                                                           From Mar. 15                                                                            To                                                            at 5 Hours Per                                                                         on - 5:30 PM                                                                            Apr. 15                                    SPRING                                                                               to  to   to  Night                                                             65° F                                                                       80° F                                                                        75° F                                                                       of 7-10 f.c.                                                                           Off - 7:30 AM                                                                           300 ppm                                          62° F                                                                       70° F                                                                        65° F                                                                       1 to 2 weeks                                                                   at 3 Hours Per                                                                         On - 6:00 PM                                        SUMMER                                                                               to  to   to  Night            NONE                                             68° F                                                                       90° F                                                                        75° F                                                                       of 7-10 f.c.                                                                           Off - 8:00 AM                                       __________________________________________________________________________

                                      CHART B                                      __________________________________________________________________________     COMPARISON OF YELLOW FROST AND FROST                                                          DIAMETER ACROSS           FLOWERING                                                                              CAPITULUM                            RAY FLORET                                                                             FACE OF     PLANT BRANCHING                                                                              RRSPONSE                                                                               FORM AND                      CULTIVAR                                                                              COLOR   CAPITULUM   HEIGHT                                                                               PATTERN PERIOD  TYPE                          __________________________________________________________________________     Yellow Frost                                                                          Medium  80 to 95 mm.                                                                               Medium                                                                               Semi-   9 week  Flat                                 Yellow                    spreading       Spoon Daisy                   Frost  White   80 to 95 mm.                                                                               Medium                                                                               Semi-   9 week  Flat                                                           spreading       Spoon Daisy                   __________________________________________________________________________      COMPARISONS MADE OF PLANTS GROWN IN A GREENHOUSE IN BARBERTON, OHIO UNDER      ENVIRONMENTAL CONDITIONS AS DESCRIBED IN CHART A.                         

We claim:
 1. A new and distinct cultivar of Chrysanthemum morifolium Ramat, known by the cultivar name Yellow Frost and particularly characterized as to uniqueness by the combined characteristics of spoon daisy capitulum type; flat capitulum form; medium yellow ray floret color; yellow green (immature) to yellow (mature) disc floret color; diameter across face of capitulum from 80 to 95 mm. at maturity; uniform nine week flowering response to photoperiodic short-day control; medium plant height; semi-spreading branching pattern; and minimal pollen development. 